Fluid pressure motor with extensible and retractable part

ABSTRACT

A fluid pressure motor is mounted at the head of a vertically extending shaft for being oscillated or turned forth and back thereby about the axis of the shaft. The motor is provided with a part extensible and retractable laterally of the shaft. The axis of the shaft is coincident with the line of intersection of a plane extending longitudinally of the fluid pressure motor and a plane extending transversely thereof. The weight of the fluid pressure motor on one side of either of said planes substantially balances the weight of the fluid pressure motor on the other side of the plane.

United States Patent [191 Hirsch et al.

[ FLUID PRESSURE MOTOR WITH EXTENSIBLE AND RETRACTABLE PART [75]Inventors: Richard Hirsch, Plymouth Meeting; Joseph F. Tomezsko,Philadelphia, both of Pa.

[73] Assignee: Paramount Precision Products, Inc.,

Philadelphia, Pa.

[22] Filed: June 15, 1971 [21] Appl.No.: 153,214

UNITED STATES PATENTS Faure 198/24 May 29,1973

3,229,829 l/l966 Weatherbee ..2l4/82 Primary Examiner-Gerald M. ForlenzaAssistant Examiner-George F. Abraham Attorney-'Louis V. Schiavo [57]ABSTRACT A fluid pressure motor is mounted at the head of a verticallyextending shaft for being oscillated or turned forth and back therebyabout the axis of the shaft. The motor is provided with a partextensible and retractable laterally of the shaft. The axis of the shaftis coincident with the line of intersection of a plane extendinglongitudinally of the fluid pressure motor and a plane extendingtransversely thereof. The weight of the fluid pressure motor on one sideof either of said planes substantially balances the weight of the fluidpressure motor on the other side of the plane.

4 Claims, 7 Drawing Figures PATENIEBHAYZS I973 SHEET 1 BF 3 8 mm inINVENTOR5 RICHARD. HIRECH BY JOSEPH F. TOM ZSKO ATTORNEY.

PATENIE W29 I973 SHEET 3 OF INVENTORS RICHARD 01.414 }/0/$L4/UZ7ATTORNEY.

HIRSCH BY JgSEPH F. TOMEZSKO FLUID PRESSURE MOTORWITI-I EXTENSIBLE ANDRETRACTABLE PART BACKGROUND OF THE INVENTION 1. Field of the InventionThis invention relates generally to glassware forming machines, andparticularly to a fluid pressure motor with an extensible and retractedpart operable for transferring newly formed glassware from a stationaryplatform or deadplate onto a continuously movingconveyor.

2. Description of the Prior Art A glassware forming machine, such as thewellknown Hartford I. S. machine, may comprise a plurality of sectionseach including a stationary deadplate at a first station for receivingnewly formed glassware, a continuously moving conveyor and means fortransferring the glassware from the deadplate onto the conveyor forbeing advanced thereby to a second station. The deadplate and conveyorof one section of the machine may be assembled to the right hand, whilethe deadplate and conveyor of another section of the machine may beassembled to the left hand. Otherwise the sections may be alike. Theconventional transfer means with which such right and left hand sectionsare furnished are not interchangeable because they themselves areconstructed to the right and left hand. In addition, the conventionaltransfer means is in the form of a' fluid pressure motor mounted uponthe head and wholly to one side of a vertically extending shaft whichoscillates the motor about the axis of the shaft. The eccentric load onthe shaft causes undue wear on certain parts of the motor and on themechanism for oscillating the same. Furthermore, the fluid pressuremotor is provided with an extensible and retractable part, but lacks anymeans for selectively adjusting the length of the stroke. Still further,the extensible and retractable part of the fluid pressure motor includesonly one piston, as a consequence of which means, such as guide rods,have been employed to secure the piston against turning about its ownaxis.

SUMMARY OF THE INVENTION The principal object of the present inventionis to removably mount a fluid pressure motor having an extensible andretractable part at the head of a vertically extending shaft in such away that the fluid pressure motor may be used with a section of aglassware forming machine whether the dead plate and conveyor thereofare assembled to the right hand or the left hand.

Another object is to mount the fluid pressure motor centrally so thatthe weight thereof is substantially balanced on the shaft, and so thateccentric loading of the shaft is kept to a minimum.

Another object is to provide such a fluid pressure motor with built-inmeans operable for adjusting the stroke of the extensible andretractable part.

Still another object is to provide such a fluid pressure motor whereinthe extensible and retractable part comprises a pair of parallel,laterally spaced pistons interconnected to secure them against turningabout their axes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a fluidpressure motor constructed in accordance with the invention showing theextensible and retractable part partially extended, parts being brokenaway and others being shown in section;

FIGS. 2 through 4 are reduced sections respectively on lines II-II,III-III and IVIV in FIG. 1;

FIG. 5 is an exploded perspective view of the fluid pressure motor, partbeing broken away and others omitted altogether for the sake of clarity;and

FIGS. 6 and 7 are diagrammatic views showing the fluid pressure motorassociated with sections of a glassware forming machine, the sectionsbeing assembled to the right and left hands, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENT The following description isdirected to the specific embodiment of the invention disclosed in thedrawings. It is not addressed to the scope of the invention since theinvention may be practiced in a variety of forms.

Referring particularly to FIGS. 1 through 5, a fluid pressure motorconstructed in accordance with the present invention, generallydesignated 10, comprises a main body part or block 12, plates 14 and 16extending respectively across the fore and aft ends of the block 12, apair of extensible and retractable members, generally designated 17 and18, extending through the front plate 14 and into the block 12, and anadjustable stroke mechanism, generally designated 20, extending throughthe back plate 16 and into the block 12.

The block 12 is rectangular in transverse section, and in both verticaland horizontal longitudinal section, as shown. Extending longitudinallythrough the block 12 are a pair of parallel, laterally spacedcylindrical bores or cylinders 22. At the fore end of the block 12,between the cylinders 22, are a pair of communicating bores 24 and 26,these bores opening respectively on the bottom and the fore end of theblock. At the aft end of the block 12, between the cylinders 22, are aseries of communicating bores 28, 30, 32 and 33, the bores 28 and 33opening respectively on the bottom and the aft end of the block.

Axially aligned respectively with the cylinders 22 in the block 12 andextending from front to back through front plate 14 are a pair of bores34 terminating in counterbores 36. Pressed into each bore 34 is abushing 38 provided with a radially outwardly extending flange 40 nestedin the associated counter-bore 36. It will be noted that the thicknessof the flange 40 is less than the depth of the counterbore 36, as shown.The inner face of the front plate 14 is provided with a groove 42extending horizontally between and interconnecting the counterbores 36.Threaded into the top of the front plate are a pair of fittings 43,respectively directly over the bushings 38. The inner surface of eachbushing 38 may be lubricated through the associated fitting 43 and anoil passage (not shown) placing the fitting in communication therewith.The front plate 14 is secured to the fore end of the block 12 by meansof eight studs 44 which extend freely through holes 46 in the plate andthread into holes 48 in the fore end of the block 12. When the frontplate 14 is secured in place, the groove 42 communicates with the bore26.

Axially aligned with one of the cylinders 22 in the.

block 12 and extending from back to front through the back plate 16 is abore 50 terminating in a counterbore 52. The inner face of the backplate 116 is provided with a groove 54 extending radially outwardly fromthe counterbore 52 and across the longitudinally extending verticallydisposed median plane of the block 12.

Threaded into the top of the back plate 16 is a needle valve 55communicating with the groove 54 through a suitable passage (not shown).The back plate 16 is secured to the aft end of the block 12 by means ofeight studs 56 which extend freely through holes 58 in the plate andthread into holes (not shown) in the aft end of the block 12. When theback plate is secured in place, the groove 54 communicates with the bore33.

The extensible and retractable member 17 comprises a solid piston rod 62slidably passing through one of the bushings 38 and extending into theassociated cylinder 22 in the block 12. The inner end portion of the rod62 mounts a piston 64 fitted with a pair of axially spaced piston rings66. The extensible and retractable member 18 comprises a piston rod 68slidably passing through the other bushing 38 and extending into theassociated cylinder 22 in the block 12. The inner end portion of the rod68 mounts a piston 70 fitted with a pair of axially spaced piston rings72. The fore end portion of the rod 68, designated 74, is solid, whilethe remainder of the rod 68, designated 76, is hollow. Threaded into theinner end portion of the hollow section 76 is a lock collar 78 providedwith a central opening 80.

The piston rods 62 and 68 mount a pusher plate 82 extending horizontallyacross the fore ends thereof and secured to each rod by 'a pair of studs84 extending freely through the pusher plate and threaded into holes 86in the fore ends of the rods. The pusher plate in turn mounts a pair oflaterally spaced pusher arms 88 extending horizontally forwardly fromthe pusher plate. It will be understood that the pusher plate and pusherarm assembly may take various forms, depending upon the mode ofoperation and the work to be accomplished, e.g., preferably, the pusherarms are adjustably secured in position along the pusher plate andvertically relative to the pusher plate to accommodate glassware ofdifferent size.

The adjustable stroke mechanism 20 comprises a guide bar 90 pressed intothe hollow section 76 of the piston rod 68 and extending from the solidfore end portion 74 of the piston rod 68 to the lock collar 78. The bar90 is provided with a groove 92 extending the full length thereof andaccommodating a correspondingly shaped slide 94. Extending freelythrough the opening 80 in the lock collar 78 and threaded through theslide 94 is the fore end of a rod 96, which carries a cotter pin 97. Theaft end portion of the rod 96 is provided with a head 98 nested in thebore 50. Under the head 98 is a lock member 100 affixed to the rod 96and nested in the counterbore 52. The lock member is provided withaxially spaced circumferentially extending grooves 102 and 104 and adimple 106. The groove 102 accommodates an O-ring 108. The lower endportion ofa pin 110 which is pressed into an opening 111 projects intothe groove 104. The dimple 106 accommodates a spherical detent 112 atthe inner end of a hole 114. Threaded into the outer end of the hole 114is a set screw 116, and interposed between the detent and the set screwis a compression spring 118.

The fluid pressure motor is seated upon a base or swival plate 120provided with parallel, laterally spaced bores 122 and 123 communicatingrespectively with the bores 24 and 28 in the block 12.

The base plate 120 in turn is seated upon a plate 124 which is providedwith parallel, laterally spaced bores 126 and 127 communicatingrespectively with bores 122 and 123 in the plate 120. The plate 124 isin the form of aIICOllflI affixed to an upper end portion of avertically extending shaft 128. The upper end portion of the shaft isdetachably projected into an opening 130 in the base plate 120. A pairof studs 132 extend downwardly freely through openings 134 in the block12 and openings 136 in the plate 120 and are threaded into openings 138in the plate 124.

It will be observed that the bore 126 in the plate 124, bore 122 in theplate 120, bores 24 and 26 in the block 12 and the groove 42 in thefront plate 14 conjointly provide an air passage 140 communicating withthe fore ends of the cylinders 22, and that the bore 127 in the plate124, bore 123 in the plate 120, bores 28, 30, 32 and 33 in the block 12,and the groove 54 in the back plate 16 conjointly provide an air passage142 communicating with the aft ends of the cylinders 22. It will also beobserved that the fluid pressure motor 10 is centrally mounted upon theshaft 128, i.e., the axis of the shaft 128 is disposed in alongitudinally extending vertically disposed plane midway between theextensible and retractable members 17 and 18.

Fluid motor 10 is operated pneumatically. Suitable conduits (not shown)from a source of pressurized air are connected to the underside of theplate 124 for supply of air respectively to cylinders 22 through thepassages 140 and 142. Referring particularly to FIG. 1, the piston rods62 and 68 are shown partially extended. Air under pressure is introducedthrough the passage 142 to the aft ends of the cylinders 22. If desired,the pressure may be reduced by bleeding air through the needle valve 55.At the same time the fore ends of the cylinders 22 are vented toatmosphere through the passage 140. As a consequence, the pusher plate82 and piston rods 62 and 68 are extended. The limit of traverse isreached when the lock collar 78 engages the stop 94. After apredetermined period of time, air under pressure is introduced throughthe passage 140 into the fore ends of the cylinders 22, and at the sametime, the aft ends of the cylinders 22 are vented to atmosphere throughthe passage 142. As a consequence, the pusher plate 82 and piston rods62 and 68 are retracted. The limit of traverse is reached when thepusher plate 82 engages the front plate 14 or the heads of the studs 44.

The length of the stroke may be adjusted to suit the work to be done. Atool is applied to the head 98 of the rod 96 and the rod is turned toposition the stop 94 in a selected position longitudinally of the rod96. The cotter pin 97 guards against threading the stop 94 off the rod96. Lock member is secured against axial movement by the lower endportion of the pin engaged in the groove 104. The O-ring 108 preventsescape of air past the lock member 100. When the head 98 of the rod 96is turned, the rod 96 and the lock member 100 are also turned and thespherical detent 102 is forced out of the dimple 106 against theinfluence of the compression spring 118. As the rod is turned, the slidemoves axially of the rod 96 to the selected position which affords thestroke desired.

The fluid pressure motor 10 of this invention is intended for replacingthe corresponding fluid pressure motor of US. Pat. No. 3,249,200, issuedMay 3, 1966, to G. E. Rowe. Reference may be had to said patent for thebasic glassware forming machine, and particularly for the arrangementfor oscillating the fluid pressure motor about a vertically extendingaxis and for the mode of operation of said arrangement.

Referring particularly to FIGS. 6 and 7, which show the fluid pressuremotor 10 in the environment for which it is intended, newly formed glassbottles 144 are deposited upon a deadplate 146. The function of themotor 10 is to push or sweep these bottles from the deadplate onto theconveyor belt 148. As shown in full lines, the motor 10 faces thedeadplate and the pusher plate and piston rods are in retractedpositions. The latter are then extended to the broken line positionthereof, over the deadplate, so that the pusher arms 88 are disposedrespectively behind the bottles 144. Thereupon, the shaft 128 makes aquarter turn, swinging the motor 10 to the dotted line position thereof,over the conveyor belt 148. The bottles 144 are thereby swept in anarcuate path before the pusher arms 88 to the dotted line positionsthereof over the conveyor belt 148. Thereupon, the pusher plate andpiston rods are retracted to prevent interference with the movement ofbottles on the conveyor belt. The shaft 128 is now turned back to itsinitial position, whereupon the motor 10, piston rods and pusher plateassume the full line positions thereof, thus completing a full cycle ofoperation.

If the motor 10 is in use with a section of the glassware formingmachine assembled to one hand and it is desired to transfer it to asection of the glassware forming machine assembled to the opposite hand,after detaching it from the plate 124 and shaft 128 of the first sectionand before mounting it upon the plate 124 and shaft 128 of the secondsection, it is only necessary to reverse the pusher plate 82. Thus itwill be noted that the fluid pressure motor 10 is suited for use in asection of the glassware forming machine whether the section, i.e., thedeadplate and conveyor, is assembled to the right hand, as in FIG. 6, orto the left hand, as in FIG. 7. Furthermore, it will be noted that thefluid pressure motor is centrally mounted, i.e., the weights of theparts thereof on opposite sides or fore and aft, with respect to theshaft 128, are substantially equal.

Referring particularly to FIGS. 6 and 7, when it is desired to detachthe motor 10 from the plate 124 and shaft 128, it is necessary to reachover the hot glassware carried by the conveyor belt 146. Accordingly, itis convenient to have the motor 10 and swival plate 120 attached to theplate 124 by means of studs 132, which extend downwardly through theblock 12, with heads fully exposed for easy application of a toolthereto.

While in accordance with the provisions of the patent statutes, 1 haveillustrated and described the best form of the embodiment of myinvention now known to me, it will be apparent to those skilled in theart that changes may be made in the form of the apparatus describedwithout departing from the spirit and scope of the invention as setforth in the appended claims, and that in some cases certain features ofmy invention may be used to advantage without a corresponding use ofother features.

What is claimed is:

1. ln apparatus for transferring glassware from a deadplate onto acontinuously moving conveyor, the combination comprising A. a verticallyextending shaft,

B. means for oscillating said shaft about its axis through a substantialangle between a first and a second position,

C. a fluid pressure motor carried by said shaft includl. a pair oflaterally spaced, parallel members extensible and retractable laterallyrelative to the axis of said shaft, the axis of said shaft beingdisposed substantially midway between said mem- 5 bers,

D. means on said shaft providing a seat for said fluid pressure motorand detachably affixing it to said shaft for movement therewithincluding 1. a collar plate extending cross-axially of and affixed tothe upper end portion of said shaft,

2. a base plate seated upon said collar plate and in turn providing aseat for said fluid pressure motor, a portion of said shaft extendingupwardly from said collar plate being detachably projected into anopening in said base plate, and

3. means projected downwardly freely through the main body of said fluidpressure motor and through said base plate and threaded into said collarplate,

E. work engaging means carried by said pair of members for beingextended and retracted threrewith, and

F. means for oscillating said fluid pressure motor about the axis ofsaid shaft and for extending and retracting said pair of members andsaid work engaging means in predetermined timed relation in repeatingcycles for transferring work from said deadplate to said conveyor.

2. In apparatus for transferring glassware from a 30 deadplate onto acontinuously moving conveyor, the

combination comprising A. a vertically extending shaft, B. means foroscillating said shaft about its axis through a substantial anglebetween a first and a second position, C. a fluid pressure motor carriedby said shaft includmg l. a block having a pair of laterally spaced,parallel cylinders,

2. front and back plates respectively extending across the fore and aftends of said block,

3. a pair of pistons respectively workable in said cylinders, and

4. a pair of piston rods extending forwardly respectively from saidpistons and through said front plate, said pistons and piston rods beingextensible and retractable laterally relative to the axis of said shaft,

D. means on said shaft providing a seat for said fluid pressure motor,

E. means projected downwardly through said block and detachably securingsaid fluid pressure motor in position on said seating means,

F. interconnecting passage sections respectively in said motor seatingmeans and fluid pressure motor for placing a source of pressurized airin communication with the fore ends of said cylinders for retractingsaid pistons including an air passage section in the form of an opengroove extending across the inner face of said front plate and havingopposite end portions in communication respectively with the fore endsof said cylinders,

G. interconnecting passage sections respectively in said motor seatingmeans and fluid pressure motor for placing said source of pressurizedair in communication with the aft ends of said cylinders for extendingsaid pistons including an air passage section in the form of an opengroove extending across the inner face of said back plate and havingopposite end portions in communication respectively with the aft ends ofsaid cylinders, H. work engaging means carried by said pair of pistonrods for being extended and retracted therewith, and 1. means foroscillating said fluid pressure motor about the axis of said shaft andfor extending and retracting said pair of pistons and said work engagingmeans in predetermined timed relation in repeating cycles fortransferring work from said deadplate to said conveyor. 3. Thecombination according to claim 2 wherein the fore end of each cylindercommunicates with the associated end of the air passage section providedby the groove extending across the inner face of the front plate throughan annular space extending about the piston rod and provided by a recessin the inner face of the front plate.

4. In apparatus for transferring glassware from a deadplate onto acontinuously moving conveyor, the combination comprising A. a verticallyextending shaft, B. means for oscillating said shaft about its axisthrough a substantial angle between a first and a second position, C. afluid pressure motor carried by said shaft includmg l. a block having apair of laterally spaced parallel cylinders and detachably affixed tothe head of said shaft for oscillating therewith,

2. front and back plates respectively extending across the fore and aftends of said block,

3. a pair of pistons respectively workable in said cylinders, and

4. a pair of piston rods extending forwardly respectively from saidpistons and through said front plate, said pistons and piston rods beingextensible and retractable laterally relative to the axis of said shaft,and one of said piston rods being provided with a hollow inner endsection,

D. means operable for selectively adjusting the outward stroke ortraverse of the piston and piston rod assembly working in said cylindersincluding,

1. a stop disposed in the hollow of said piston rod section,

2. a rod extending through the back plate forwardly into the hollow ofsaid piston rod section, the fore end of said rod being threaded throughsaid stop, and the aft end of said rod being fully exposed at the outerface of said back plate for application of a tool thereto, and 3. meansfor securing the rod against axial movement including a. a cylindricallock member provided with a pair of axially spaced circumferentiallyextending grooves,

b. an O-ring accommodated by one of said grooves for pneumaticallysealing the opening in which said lock member is nested, and

0. one end portion of a pin carried by the back plate and accommodatedby the other of said grooves,

E. lock means at the inner extremity of said hollow piston rod sectionarranged for engaging said stop to thereby limit the outward stroke ortraverse of said piston and piston rod assemblies,

F. work engaging means carried by said pair of piston rods for beingextended and retracted therewith, and

G. means for oscillating said fluid pressure motor about the axis ofsaid shaft and for extending and retracting said pair of pistons andsaid work engaging means in predetermined timed relation in repeatingcycles for transferring work from said deadplate to said conveyor.

1. In apparatus for transferring glassware from a deadplate onto acontinuously moving conveyor, the combination comprising A. a verticallyextending shaft, B. means for oscillating said shaft about its axisthrough a substantial angle between a first and a second position, C. afluid pressure motor carried by said shaft including
 1. a pair oflaterally spaced, parallel members extensible and retractable laterallyrelative to the axis of said shaft, the axis of said shaft beingdisposed substantially midway between said members, D. means on saidshaft providing a seat for said fluid pressure motor and detachablyaffixing it to said shaft for movement therewith including
 1. a collarplate extending cross-axially of and affixed to the upper end portion ofsaid shaft,
 2. a base plate seated upon said collar plate and in turnproviding a seat for said fluid pressure motor, a portion of said shaftextending upwardly from said collar plate being detachably projectedinto an opening in said base plate, and
 3. means projected downwardlyfreely through the main body of said fluid pressure motor and throughsaid base plate and threaded into said collar plate, E. work engagingmeans carried by said pair of members for being extended and retractedthrerewith, and F. means for oscillating said fluid pressure motor aboutthe axis of said shaft and for extending and retracting said pair ofmembers and said work engaging means in predetermined timed relation inrepeating cycles for transferring work from said deadplate to saidconveyor.
 2. a base plate seated upon said collar plate and in turnproviding a seat for said fluid pressure motor, a portion of said shaftextending upwardly from said collar plate being detachably projectedinto an opening in said base plate, and
 2. front and back platesrespectively extending across the fore and aft ends of said block,
 2. Inapparatus for transferring glassware from a deadplate onto acontinuously moving conveyor, the combination comprising A. a verticallyextending shaft, B. means for oscillating said shaft about its axisthrough a substantial angle between a first and a second position, C. afluid pressure motor carried by said shaft including
 2. front and backplates respectively extending across the forE and aft ends of saidblock,
 2. a rod extending through the back plate forwardly into thehollow of said piston rod section, the fore end of said rod beingthreaded through said stop, and the aft end of said rod being fullyexposed at the outer face of said back plate for application of a toolthereto, and
 3. means for securing the rod against axial movementincluding a. a cylindrical lock member provided with a pair of axiallyspaced circumferentially extending grooves, b. an O-ring accommodated byone of said grooves for pneumatically sealing the opening in which saidlock member is nested, and c. one end portion of a pin carried by Theback plate and accommodated by the other of said grooves, E. lock meansat the inner extremity of said hollow piston rod section arranged forengaging said stop to thereby limit the outward stroke or traverse ofsaid piston and piston rod assemblies, F. work engaging means carried bysaid pair of piston rods for being extended and retracted therewith, andG. means for oscillating said fluid pressure motor about the axis ofsaid shaft and for extending and retracting said pair of pistons andsaid work engaging means in predetermined timed relation in repeatingcycles for transferring work from said deadplate to said conveyor.
 3. apair of pistons respectively workable in said cylinders, and
 3. Thecombination according to claim 2 wherein the fore end of each cylindercommunicates with the associated end of the air passage section providedby the groove extending across the inner face of the front plate throughan annular space extending about the piston rod and provided by a recessin the inner face of the front plate.
 3. a pair of pistons respectivelyworkable in said cylinders, and
 3. means projected downwardly freelythrough the main body of said fluid pressure motor and through said baseplate and threaded into said collar plate, E. work engaging meanscarried by said pair of members for being extended and retractedthrerewith, and F. means for oscillating said fluid pressure motor aboutthe axis of said shaft and for extending and retracting said pair ofmembers and said work engaging means in predetermined timed relation inrepeating cycles for transferring work from said deadplate to saidconveyor.
 4. In apparatus for transferring glassware from a deadplateonto a continuously moving conveyor, the combination comprising A. avertically extending shaft, B. means for oscillating said shaft aboutits axis through a substantial angle between a first and a secondposition, C. a fluid pressure motor carried by said shaft including
 4. apair of piston rods extending forwardly respectively from said pistonsand through said front plate, said pistons and piston rods beingextensible and retractable laterally relative to the axis of said shaft,and one of said piston rods being provided with a hollow inner endsection, D. means operable for selectively adjusting the outward strokeor traverse of the piston and piston rod assembly working in saidcylinders including,
 4. a pair of piston rods extending forwardlyrespectively from said pistons and through said front plate, saidpistons and piston rods being extensible and retractable laterallyrelative to the axis of said shaft, D. means on said shaft providing aseat for said fluid pressure motor, E. means projected downwardlythrough said block and detachably securing said fluid pressure motor inposition on said seating means, F. interconnecting passage sectionsrespectively in said motor seating means and fluid pressure motor forplacing a source of pressurized air in communication with the fore endsof said cylinders for retracting said pistons including an air passagesection in the form of an open groove extending across the inner face ofsaid front plate and having opposite end portions in communicationrespectively with the fore ends of said cylinders, G. interconnectingpassage sections respectively in said motor seating means and fluidpressure motor for placing said source of pressurized air incommunication with the aft ends of said cylinders for extending saidpistons including an air passage section in the form of an open grooveextending across the inner face of said back plate and having oppositeend portions in communication respectively with the aft ends of saidcylinders, H. work engaging means carried by said pair of piston rodsfor being extended and retracted therewith, and I. means for oscillatingsaid fluid pressure motor about the axis of said shaft and for extendingand retracting said pair of pistons and said work engaging means inpredetermined timed relation in repeating cycles for transferring workfrom said deadplate to said conveyor.